A Fast Transient-Current Control Strategy in Sensorless Vector-Controlled Permanent Magnet Synchronous Motor

This letter presents a current control technique for fast transient-current response in a sensorless vector-controlled permanent magnet synchronous motor. Pontryagin's maximum principle is employed to derive the time-optimal voltage solution. Based on this principle, the technique can guarantee the current vector transition from one operating point to another with minimum time. Compared to a proportional-integral controller, the current response by using the time-optimal controller is much faster, even under a limited dc bus voltage. Experiments are carried out to substantiate the proposed technique